A member having a closed-bottom hole portion that is used for a carbonaceous crucible has been manufactured by hollowing out an inner portion of a raw material made of a carbonaceous material using a working tool (see Patent Document 1 below). The manufacturing method described in Patent Document 1 is as follows. A raw material made of a carbonaceous material is rotated, and a groove digging tool is pressed against an end face of the raw material to dig the material, so as to form a cylindrical trench in which a saw blade can be inserted, whereby a hollowed-out side portion is formed. Next, the groove digging tool removed, and a tool having a saw blade mounted to its distal end is inserted in the cylindrical trench. This tool for forming a hollowed-out bottom portion supports the saw blade at one point of the distal end, and it is configured so that the saw blade can be rotated around the support point. Then, after inserting the saw blade into the bottom of the cylindrical trench, the saw blade is rotated to cut the raw material by pressing the saw blade in a direction approaching the central portion of the raw material, so that the hollowed-out bottom portion is formed.